Deep level transient spectroscopy studies of Er and Pr implanted GaN films

Abstract

Deep level transient spectroscopy measurements were used to characterize the ele ctrical properties of metal organic chemical vapor deposition grown undoped, Er- implanted and Pr-implanted GaN films. Only one deep level located at 0.270 eV be low the conduction band was found in the as-grown GaN films. But four defect le vels located at 0.300 eV, 0.188 eV, 0.600 eV and 0.410 eV below the conduction b and were found in the Er-implanted GaN films after annealing at 900 ℃ for 30 mi n, and four defect levels located at 0.280 eV, 0.190 eV, 0.610 eV and 0.390 eV b elow the conduction band were found in the Pr-implanted GaN films after annealin g at 1050 ℃ for 30min. The origins of the deep defect levels are discussed. Aft er annealing at 900℃ for 30min in a nitrogen flow, Er-related 1538nm luminescen ce peaks could be observed for the Er-implanted GaN sample. The energy-transfer and luminescence mechanism of the Er-implanted GaN film are described.